In bi-directional communications systems of the related art, a ground station transmits and receives signals to and from a satellite, and the satellite, in turn, transmits and receives signals to and from a mobile platform. Typically, a plurality of satellites are present that cover particular geographic regions, and each satellite further includes a plurality of transponders that receive data from the ground station and relay the data to the mobile platform. In addition, the mobile platform includes receive and transmit antennas, which are used to communicate with the satellite transponders and relay data to the ground station.
For mobile platforms that transmit data, UTC (Universal Time Code) regulations require that the mobile platform receive authorization to continue transmitting within a thirty (30) second interval. If the mobile platform does not receive authorization to continue transmitting from the ground station within the thirty (30) second interval, the mobile platform must terminate transmission of data. The authorization is generally transmitted from the ground station to the mobile platform, via the transponder, in a separate signal that contains only an authorization message. Since there exist several other data transmissions between the ground station and the mobile platform, the authorization message signal increases the number of transmissions and the associated time and cost in managing the transmissions from the ground station. The more data signals that are transmitted to the mobile platform, the greater the complexity and cost of the overall communications system.
Accordingly, there remains a need in the art for a communications system that can use other data signals of a communications system to authorize transmission in order to increase operational efficiency and reduce overall costs.